Re: Recursive use of make

[Paul D. Smith]

%% address@hidden writes:

  l> Hi, im trying to write a makefile to manage a C++ object oriented
  l> project. I have a top level makefile that defines and exports a
  l> variable. When i call a sub-makefile this variable gets new text
  l> appended to it. I need to use the new text in the top-level
  l> makefile, but when make finishes the processing of the sub-makefile
  l> the text that was appended dissapear. How can I use in a top-level
  l> makefile the values that a sub-makefile appends to a exported
  l> variable?

You can't.  Every recursive invocation of make is a separate process,
every process has its own set of variables, and the variable settings in
that process cannot be passed back to the parent process.  Just like
when you start a new shell and change a variable there, it cannot
propagate back up to the process that invoked the shell.

-- 
-------------------------------------------------------------------------------
 Paul D. Smith <address@hidden>          Find some GNU make tips at:
 http://www.gnu.org                      http://make.paulandlesley.org
 "Please remain calm...I may be mad, but I am a professional." --Mad Scientist